1. Field of the Invention
The present invention relates to a method of manufacturing a semiconductor device, and more particularly, to a method of manufacturing a semiconductor device having a fin structure including using only one photomask to form a feature mask larger than the fin structure and a fin cutting mask for defining the fin structure.
2. Description of the Prior Art
Conventional planar metal-oxide-semiconductor (MOS) transistor has difficulty when scaling down to 65 nm and below. Therefore the non-planar transistor technology such as Fin Field effect transistor (hereinafter abbreviated as FinFET) technology that allows smaller size and higher performance is developed to replace the planar MOS transistor.
Since the FinFET includes a fin structure, the overlapping area between a gate electrode and the fin structure can be increased, and the channel width is accordingly increased. The fin structure is conventionally formed by: First a sacrificial mandrel is formed by performing a photolithographic process with a first photomask. A spacer is formed on sidewalls of the sacrificial mandrel to surround the sacrificial mandrel by performing a deposition process and an etching back process, and the sacrificial mandrel is removed. Next, the spacer is cut by performing a fin cutting process with a second photomask to form two fin structures.
Besides forming the FinFET, the conventional method of manufacturing a semiconductor device including the FinFET and other devices larger than the FinFET requires extra processes and photomasks to form the other devices, which limits the manufacturing cost. Therefore, a method of manufacturing a semiconductor device with reduction to the manufacturing cost is always in need.